The Internet is becoming a primary method for distributing media content (e.g., video and audio or just audio or just video) and other information to end users. It is currently possible to download music, video, games, and other media information to computers, cell phones, and virtually any network capable device. The percentage of people accessing the Internet for media content is growing rapidly. The quality of the viewer experience is a key barrier to the growth of video viewing on-line. Consumer expectations for online video are set by their television and movie viewing experiences.
Audience numbers for streaming video on the web are rapidly growing, and there are a growing interest and demand for viewing video on the Internet. Streaming of data files or “streaming media” refers to technology that delivers sequential media content at a rate sufficient to present the media to a user at the originally anticipated playback speed without significant interruption. Unlike downloaded data of a media file, streamed data may be stored in memory until the data is played back and then subsequently deleted after a specified amount of time has passed.
The process for preparing media content for adaptive streaming typically involves taking a source file, such as a movie, or a source feed, such as a broadcast signal, and splitting it into temporal chunks or slices of media (e.g., video and audio), and encoding each slice of the media at different quality levels. Typically the different quality levels are achieved by encoding the media content at different bit rates according to encoding profiles. During playback, and as network conditions fluctuate, a consuming application selects a slice at one of the different quality levels that is best suited for the present network throughput, and the consuming applications adjusts the quality up or down as available bandwidth increases or decreases by selecting subsequent slices at the appropriate quality levels.
Streaming media content over the Internet has some challenges, as compared to regular broadcasts over the air, satellite, or cable. Although the adaptive streaming approach provides many advantages, one major disadvantage is that each temporal slice must be encoded multiple times, often a dozen or more, depending on the desired number of quality levels and playback devices or platforms. This requires some time and upfront resource costs. In particular, the computational resources required to encode into the multiple formats is often quite large, as is the necessary bandwidth required to move the encoded slices to their location on a web server from which they are served during playback. This encoding process also takes some time. Also, there may be storage costs associated with storing multiple encodings of the media content. For example, a content provider may have a very large library of media. When encoding the media for adaptive streaming, the content provider has to encode the media into the different quality levels and store the multiple copies of the media at the different quality levels for subsequent adaptive streaming to clients. The encoding and storage costs may be justified when the media is popular and is streamed to various clients. However, if the media is not popular, the encoding and storage of multiple copies of that media may not justify the associated cost. These costs for less popular media and even user-created content or user-uploaded content, may prevent content providers and some users from storing this media content online in a format for adaptive streaming.